A liquid crystal panel as this type of display element is designed so as to have a panel main body including an array substrate, a counter substrate and a liquid crystal layer interposed therebetween, and the panel main body has a plurality of pixels arranged in a matrix form. Thin film transistors (TFT) as switching elements for driving pixels are arranged in connection with the pixels on an array substrate, and also gate lines and signal lines which correspond to scan lines as signal wires electrically connected to the gate electrodes and the source electrodes of these thin film transistors are arranged in a grid form. Furthermore, driver ICs as driving means are electrically connected to the end portions of the gate lines and the signal lines on the array substrate. That is, this liquid crystal panel is a so-called COG (Chip On Glass) type.
The process of manufacturing the liquid crystal panel as described above contains a step of inspecting wire breaking or short-circuiting of the gate lines or the signal lines, and an inspection circuit having inspection TFTs as inspection switching elements is provided to the end portions of the gate lines and the signal lines.
In this inspecting step, the inspection TFTs are turned on to supply a predetermined inspection signal to the gate lines and the signal lines, and the turn-on state of the pixels are checked visually, whereby the wire breaking or the short-circuiting of the gate lines or the signal lines can be detected.
The wire breaking or short-circuiting of the gate signals and the signal lines which are inspected in the inspecting step as described above is liable to occur in the vicinity of driver IC mounting portions corresponding to connection portions to the driver ICs because the vicinities of the driver IC mounting portions are not covered by a counter substrate. Therefore, when the inspection TFTs are disposed at the opposite end portion to the driver IC and an inspection signal is supplied from the opposite end portion, the inspection signal passes through the gate line or the signal line to the opposite end portion, and thus the pixel is turned on as in the case of the normal state. Accordingly, particularly, it is not easy to detect the wire breaking.
Therefore, as shown in Japanese Laid-Open Patent Publication NO. 2004-102260, it is preferable that the inspection TFTs are disposed at the driver IC mounting portion side and an inspection signal is supplied from the driver IC side.
However, driver ICs have been recently miniaturized in accordance with the requirement of reducing the frame size, and it has not been easy to secure a sufficient space in which the inspection TFTs are disposed.
Therefore, it has been required to miniaturize the inspection TFTs. As a result, the driving capability of the inspection TFTs is lowered, and image quality abnormalities such as unevenness or the like occur when the liquid crystal panel is inspected, which may induce erroneous decision.
The present invention has been implemented in view of the foregoing point, and has an object to provide a display element that can reliably inspect signal wires while saving the space of an inspection circuit.